Sanllehi's area of expertise is not knowing potentially great players though. He might have that sort of knowledge but there's no reason to think he does. He has our analytics department to guide him, but even then it's about picking the right player out of the many selected.
From what I have seen, Sanllehi seems the schmoozing kind that has a contact book to rival anyone. Like David Dein from days gone by. But Dein had Wenger's genius in knowing the right players to move for. Who is at the club now to make those sorts of calls?